Choose the correct option(s) with regard to mechanism of the following transformation.
Choose the correct option(s) with regard to mechanism of the following transformation.
Show Hint
- It proceeds through divinyl cyclopropane rearrangement
- It involves a diradical intermediate
- It proceeds through di-\(\pi\)-methane rearrangement
- It proceeds through [2+2+2] cycloaddition reaction
The Correct Option is B, C
Solution and Explanation
The reaction shown is a classic example of the di-\(\pi\)-methane rearrangement, a photochemical reaction. Upon irradiation with UV light, a system containing a conjugated diene and a methylene bridge undergoes a rearrangement that involves:
- Excitation of the molecule to a singlet or triplet excited state.
- Formation of a diradical intermediate.
- Rearrangement to a bicyclo[3.1.0]hexane-type product via a 1,2-shift.
Let’s evaluate each option:
- (A) Divinyl cyclopropane rearrangement is not applicable here. WRONG
- (B) Correct – the reaction proceeds via a diradical intermediate. CORRECT
- (C) Correct – this transformation is a di-\(\pi\)-methane rearrangement. CORRECT
- (D) [2+2+2] cycloaddition is not the mechanism here. WRONG
\[ \boxed{\text{Correct options: (B) and (C)}} \]
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